Catenary roll support for a conveyor belt

ABSTRACT

A catenary type roll support for a troughed conveyor belt has cylindrical segments connected solely by tapes fastened to the surfaces of the cylindrical segments, and the first and last segments are suspended from fixed supports by anti-friction bearings.

[451 Qct.24,19 72 United States Patent Stark et al.

m J m mA M MD w m U 3,068,995 12/1962 Poundstone...............l98/l92both of Akron, Ohio [73] Assignee: The B. F. Goodrich Company,- NewPrimary ExaminerRichard E. Aegerter York, Attorney-William A. Shira, Jr.and Harold S. Meyer [57] ABSTRACT A catenary type roll support for atroughed conveyor 22 Filed: Apr-i121, 1971 21] Appl.No.: 135,924

belt has cylindrical segments connected solely by tapes fastened to thesurfaces of the cylindrical segments, and the first and last segmentsare suspended from fixed supports by anti-friction bearings.

[52] US. R [51] Int. ...........B65g 15/08 [58] Field ofSearch......................................198/192 8 Claims, 5 DrawingFigures J Le CATENARY ROLL SUPPORT FOR A CONVEYOR BELT BACKGROUNDConveyor belts for bulk commodities are longitudinally folded into atrough shape to permit carriage of a maximum load without danger ofspillage and are supported on oppositely inclined troughing rolls,usually with a horizontal roll between them. Such rolls are usuallyrigidly mounted, but many proposals have been made for flexible supportsin which the usual three, or if desired more than three, rolls are hungfrom and rotate on a transverse tensioned cable or equivalent supportwhich takes the approximate shape of a catenary.

Such catenary supporting rolls have theoretical advantages, in thattheir angles are to some extent selfadjusting to conform tounsymmetrical loads, and in addition swing slightly in the direction ofmotion of the belt so as to exert a self centering force on the belt.Nevertheless, previously proposed constructions have not met with muchsuccess because of their cost resulting from complexity of construction,or because of operating problems such as excessive friction.

SUMMARY OF THE INVENTION This invention is a catenary type roll supportfor troughed conveyor belts, which has a series of axially spacedcylinders joined by a plurality of flexible ties fastened to thecylindrical surfaces, and with the first and last cylinders hung fromfixed supports on anti-friction bearings so as to be freely rotating.

The complete absence of a shaft of any kind in the catenary portion ofthe roll support is an important feature of novelty, which is largelyresponsible for the superiority of this over previously known catenarytype rolls.

Such catenary rolls are easily manufactured at reasonable cost andprovide a satisfactory support for the conveyor belts, exhibiting to thefullest extent the known advantages of this type of equipment. Theycontain only two bearings, one at each end, which are easily arrangedwith downwardly inclined openings so that they can be packed withlubricant to provide trouble free operation almost indefinitely evenwhen exposed to the weather or to other adverse influences such as dustor grit.

THE DRAWINGS In the attached drawings,

FIG. 1 is a side view of one of the catenary type belt supports of thisinvention looking lengthwise of the belt.

FIG. 2 is an enlarged sectional view of one end of the belt support,showing the nature of the connection between the several cylindricalsegments.

FIG. 3 is a sectional view of one of the cylindrical segments.

FIG. 4 is a modification of the construction shown in FIG. 2.

FIG. 5 is a view on a reduced scale of a modification of the ties inwhich they form a part of a single piece of fabric.

DETAILED DESCRIPTION Referring to FIGS. 1 and 2, the conveyor beltsupport of this invention is made up of a series of segments having theshape of rolls or cylinders 10, 11, 12, 13, and 14, which are generallyaxially aligned. Of course, when the series of cylinders is suspended inan approximately catenary shape, their individual axes are displacedfrom a straight line by a small angle. In this instance, five cylindersare shown, which is a convenient number, minimizing the angle betweensuccessive ones of the cylinders and therefore also minimizing theproblems resulting from too sharp longitudinal folding of the belt whichis supported by the cylinders.

The first and last cylinders 10 and 14 have their outward facing endsclosed by plates. One such plate 15 is shown in section in FIG. 2. To itis fastened a stub axle 16, which rotates in a bearing assembly 17 whichin turn is hung from a fixed support. The bearing assembly 17 isintegral with an eye or trunnion such as the T-bar 18 which is hooked ona fixed support such as the known oar-lock type swivel mounted doublehook 19. The book 19 and its mate on which the opposite end of thecatenary is hung may be placed on a conventional frame 20.

The inward ends of the first and last cylinders 10 and 14, and both endsof the intervening cylinders ll, 12, and 13, are formed into smoothinwardly directed curves 21. The cylinders are spaced by a distancesomewhat less than their diameter and are joined by a plurality offlexible but inextensible tapes 22 distributed around the circumferenceand extending from the outward facing end of the first cylinder 10 tothe outward facing end of the last cylinder 14.

Suitably, the cylinders are pieces of metal tubing with ends spun orswaged to form the curves 21. The

. truly cylindrical portions, but not the curves 21, are

then treated with rubber-to-metal adhesive and tapes 22 of rubberizedfabric are adhered to the entire series of cylinders, evenly spacedaround the circumference as shown in cross-section in FIG. 3.Preferably, the intervals between the tapes on the cylindrical surfacesare filled with rubber 23 of the same thickness as the tapes 22 toprovide a cylindrical support for the belt 25 as shown in FIG. 1 andFIG. 3. To protect against abrasion an additional rubber cover 24 may besuperimposed on the tapes 22 and rubber filler 23.

The several tapes are preferably constricted in the intervals betweensuccessive cylinders by wrapping with cord or by enclosing in a ring 26to form a neck as shown in FIG. 4. The inside diameter of the ring 26may be about one half the diameter of the several cylinders 10, 11, 12,13 and 14.

The rubber in which the tapes 22 are embedded, along with the addedfiller rubber 23 and wear cover 24, is preferably vulcanized while thetapes are constricted. As a result, the tapes become firmly bonded tothe cylinders by means of the adhesive but not bonded to the curved endportions 21 where there is no adhesive. At the same time thevulcanization sets the rubber in the tapes in the inwardly bent, ornecked in, constricted shape, so that each tape when not under tensiontends to return to the inwardly bent position. The ring 26 can then beremoved.

When the completed catenary support is hooked on properly spacedsupports 19, it will sag into an approximately catenary shape, theamount of sag and therefore the inclination of the first and lastcylinders 10 and 14 depending on the exact spacing of the supports,which may be made adjustable if desired. In following the catenarycurve, the successive cylinders will take positions at an angle to oneanother as shown in FIG. 1. When a conveyor belt 25 rests on such asupport, it will be folded longitudinally to the desired trough shape asa nearly smooth curve without undesirable sharp creasing if more thanthe conventional three cylinders are used, and preferably five cylindersin each support.

The angular relation of each cylinder to the ones on either side willcause the one or the pair of tapes 22 nearest the bottom, that is,nearest the outside of the catenary curve, to tend to straighten outunder the tension resulting from the weight of the catenary supportitself as well as the weight of the belt and its load. On the otherhand, all others of the tapes will be shortened and will take up a bentshape as shown at 27 in FIG. 2. The bend will tend to be inward where itwill be out of the way, but if the conveyor should be operated at such aspeed that centrifugal force becomes troublesome, the ring 26 can beretained in position as shown in FIG. 4 to give positive assurance ofretention of the tapes out of the way of possible pinching between thebelt 25 and the cylinders.

The tapes 22 can be woven or braided tapes with a selvage at each edge,or can be cut strips of woven fabric or parallel arrays of cords, as maybe found most convenient. Since the portions which are adhered to theseveral cylinders are immobilized and only the portions between thecylinders are worked, it is even possible to utilize a continuous sheetof suitable fabric wrapped completely around the several cylinders, withthe unadhered portions between the cylinders cut longitudinally'of thecylinders to form tapes, preferably with spaces circumferentially toassure flexing free from frictional engagement.

FIG. shows how-the ties or tapes 22 can form parts of a single sheet ofrubberized fabric as just described. This is a smallscale showing of theshape of the fabric before it is adhered to the cylinders. The two ends28 and 29 correspond to the outwardly facing ends of the first and lastcylinders and 14. The adjacent uncut portion 30 next to edge 28 willcover the first cylinder 10 and the other uncut portions 31, 32, 33, and34 respectively will cover the other cylinders 11, 12, 13 and 14 in thatorder. The fabric between the uncut portions is cut longitudinally,leaving ties or tapes 35 connecting the ends of the fabric. The minimumwidth of the ties 35 should have the same relation to the maximum widthof the cutouts 36 as the diameter of the ring 26 to the differencebetween its diameter and the diameter of the several cylinders 10 to 14,so that the ties will be wide enough to sustain the entire tension loadto which they will be subjected without crowding against one anotherwhen inwardly bent as at 27.

his found that the flexing of the tapes, as the cylinders rotate,consumes so little energy that this new form of catenary supportoperates almost without friction. Moreover, the simplicity offabrication, and the use of only a single pair ,of anti-frictionbearings, which can be permanently lubricated and sealed, assures areasonable first cost and little or no maintenance expense. Conse uentlthis new construction appears to make the full ene its of catenarysupports practically available to conveyor belt users for the firsttime.

Although fabric tapes arranged parallel to the axes of the cylinders arepreferred, other kinds of ties can be substituted, such as stout cords,arranged either parallel or in a criss-cross or other pattern.

Embedment of the tapes in rubber is also preferred, as it protects thefabric from deterioration and furnishes a convenient and simple means ofattachment to the cylinders. In case of operation without rings 26, therubber also provides a pronounced tendency for the tapes to fold inwardduring rotation. The same effect can be obtained with other elastomerswith the obvious changes in manufacturing procedure, or if desired forsome reason, embedment of the ties can be omitted altogether and othermeans for fastening the ties to the cylinders can be used.

We claim:

1. A catenary type roll support for a conveyor belt, comprising aplurality of generally axially aligned spaced cylinders, a series oflongitudinal flexible ties distributed around the circumference of thecylinders and. extending across the space between the cylindricalsurfaces of adjacent cylinders, the ties being fastened to the severalcylinders to connect each cylinder to the next adjacent one, and meansfor suspending the end cylinders for free rotation from fixed supports.

2. A catenary type roll support for a conveyor belt as in claim 1, inwhich the flexible ties are inextensible tapes.

3. A catenary type roll support for a conveyor belt as in claim 2, inwhich the flexible ties are fabric tapes embedded in elastomer, extendalong all of the cylinders, and are adhered to the cylinders.

4. A catenary type roll support for a conveyor belt as in claim 3, inwhich the ends of the cylinders facing another cylinder are curvedinward toward the axis of the cylinder.

5. A catenary type roll support for a conveyor belt as in claim 1, inwhich the ends of the cylinders facing another cylinder are curvedinward toward the axis of the cylinder; the flexible ties are fabrictapes embedded in rubber, extend along all of the cylinders, and areadhered to the cylindrical portions of the cylinders; and

v the cylindrical portions of the cylinders are covered with rubber toform a generally cylindrical surface.

6. A catenary type roll support for a conveyor belt as in claim 5, inwhich the tapes between cylinders are constricted by a ring smaller thanthe cylinders.

7. A catenary type roll support for a conveyor belt as in claim 5, inwhich the rubber embedding the tapes is set in an inwardly directed foldto which it tends to return when not under tension.

8. A catenary type roll support for a conveyor belt as in claim 5, inwhich the number of cylinders in each support is not less than four.

1. A catenary type roll support for a conveyor belt, comprising aplurality of generally axially aligned spaced cylinders, a series oflongitudinal flexible ties distributed around the circumference of thecylinders and extending across the space between the cylindricalsurfaces of adjacent cylinders, the ties being fastened to the severalcylinders to connect each cylinder to the next adjacent one, and meansfor suspending the end cylinders for free rotation from fixed supports.2. A catenary type roll support for a conveyor belt as in claim 1, inwhich the flexible ties are inextensible tapes.
 3. A catenary type rollsupport for a conveyor belt as in claim 2, in which the flexible tiesare fabric tapes embedded in elastomer, extend along all of thecylinders, and are adhered to the cylinders.
 4. A catenary type rollsupport for a conveyor belt as in claim 3, iN which the ends of thecylinders facing another cylinder are curved inward toward the axis ofthe cylinder.
 5. A catenary type roll support for a conveyor belt as inclaim 1, in which the ends of the cylinders facing another cylinder arecurved inward toward the axis of the cylinder; the flexible ties arefabric tapes embedded in rubber, extend along all of the cylinders, andare adhered to the cylindrical portions of the cylinders; and thecylindrical portions of the cylinders are covered with rubber to form agenerally cylindrical surface.
 6. A catenary type roll support for aconveyor belt as in claim 5, in which the tapes between cylinders areconstricted by a ring smaller than the cylinders.
 7. A catenary typeroll support for a conveyor belt as in claim 5, in which the rubberembedding the tapes is set in an inwardly directed fold to which ittends to return when not under tension.
 8. A catenary type roll supportfor a conveyor belt as in claim 5, in which the number of cylinders ineach support is not less than four.